CS Tumor Size/Ext Eval is part of the Collaborative Stage Data Collection System (CS), and was implemented in 2004. It is used to describe whether the staging basis for the AJCC T value is clinical or pathologic and to record whether systemic treatment was performed prior to assignment of either CS Tumor Size or CS Extension codes.
Some detective work is required to interpret codes in the CS Tumor Size/Ext field. The codes differ by type of cancer and occasionally by the version of CS in which the case was coded. In the PUF, CS fields are retained in the form in which they were submitted. That means that it will be necessary to identify the CS Version Numbers that are used in the PUF file, and to use those to identify whether the contents of the CS Tumor Size/Ext Eval fields may have changed over time. Links to the site-specific codes can be found at